Perennial (rarely annual) herbs or (not in Australia) small undershrubs, often glaucous. Leaves opposite, often more or less linear and parallel-veined; bracts herbaceous, leaf-like. Flowers solitary or in few-flowered dichasia, 5-merous, unisexual or bisexual; epicalyx present as 1–3 pairs of awned scales; calyx tubular, cylindric, not strongly veined with scarious seams, 5-lobed; petals long-clawed, exceeding calyx; coronal scales absent; stamens 10; ovary 1-celled, with several ovules, styles 2. Capsule cylindric to narrow-ovoid, opening by 4 short teeth; carpophore very short, sometimes absent; seeds several, ovate-scutate, dorsiventrally compressed, finely tuberculate or smooth.